The Mariners adjusted their starting rotation by pushing pitchers Felix Hernandez and Chris Young back a day, bumping Hernandez from starting Sunday against the Chicago White Sox to Monday’s series opener against Toronto.

But manager Lloyd McClendon insisted the shuffling of the rotation wasn’t to match up Hernandez against the Blue Jays, one of the teams the Mariners are chasing in the wild card, but instead to give him an extra day of rest.

“Nothing to do with Toronto,” McClendon said.

Hernandez will pitch Monday, Chris Young will pitch Tuesday and Hisashi Iwakuma will start Wednesday. McClendon said he used the same rationale he has all season to adjust the rotation.

“I told you guys: Every chance I get to give them an extra day of rest, I’m going to do it,” he said. “I think we’ve done OK with it. Last time I checked, we had the best pitching in the American League. Why break something that’s not breaking? Keep doing. Keep resting them. Keep protecting them.”

That leaves a vacant starting spot on Sunday. McClendon said he hasn’t decided on who will start, but said Taijuan Walker, Erasmo Ramirez or a reliever are possible.

Walker gave up eight runs in his last minor-league start for Class AAA Tacoma.

Jackson ‘prototypical’ leadoff hitter

McClendon listed a number of reasons why he liked adding center fielder Austin Jackson at the trade deadline: his defense, his on-base percentage, the fact he is under contract for next season. But McClendon also offered a rather unorthodox explanation for how Jackson could improve the Mariners’ lineup.

“I think he’s a prototypical leadoff hitter,” McClendon said. “This may sound strange, but he’s not afraid to strike out 3-2 looking. If you’re going to be a good leadoff hitter, you’ve got to take your walks and you have to have the ability to take close pitches 3-2 to get walks. And I think he understands that 3-2 is not an automatic fastball count in today’s world of baseball.”

Jackson has a .331 on-base percentage this season, and he has a career .342 on-base percentage. James Jones, who previously hit leadoff for the Mariners, had a .287 on-base percentage this season.

Jayson Jenks: 206-464-8277 or jjenks@seattletimes.com; on Twitter: @jaysonjenks. Jayson Jenks covers the Seahawks for the Seattle Times. He also provides coverage of other Seattle-area teams throughout the year.